The present invention relates in general to detecting cell conditions and more particularly to detection of malignant or dysplastic cells by inducing absorption of radioactive gallium from an inoculant solution by a tissue sample which may contain malignant or dysplastic cells together with normal cells and subsequently measuring gallium content of the cells using radioactivity detection methods to produce signals correlatable with the number of malignant or dysplastic cells in the tissue sample because of the tendency of the malignant or dysplastic cells to preferentially absorb the gallium relative to absorption by the normal cells. It is a particular feature of the invention that the sensitivity of such processing is substantially enhanced, through modification of the inoculation solution, without substantial increase of cost, processing steps, or calibration effort. Such benefits in sensitivity are particularly useful in connection with automating the cell examination process phase of the Papanicolau (PAP hereinafter) smear analysis process.
Non-automated PAP test processing involves smearing scrapings from the cervix upon a slide. The slide is stained with several dyes and a trained cytotechnician observes the slide under a microscope looking for cells meeting criteria of malignancy. One slide examination typically takes a technician 15 minutes for a negative specimen. Typically, there are only 55 positives in 10,000 specimens. When positives are detected, a cytopathologist is consulted. Present manual testing procedures of pre-screening by cytotechnicians involve substantial wasted time of these skilled and expensive personnel. The state of the art on automation of PAP smear analysis to eliminate, in substantial part, the cost and time delays of sample processing are described in "Summary of State-of-the-Art Workshop on Papanicolau Smear Analysis," edited by Ramsey-Klee in April, 1970, available from the Clearing House for Federal Scientific and Technical Information, Springfield, Va. and National Technical Information Service, Washington, D.C.; prior U.S. Pat. No. 3,912,929 granted Oct. 14, 1975 and U.S. Pat. No. 3,857,033 granted Dec. 24, 1974, and references therein cited, all of which are incorporated herein by reference. U.S. Pat. No. 3,912,929 particularly describes automated cell-by-cell examination comprising formation of a solution containing radioactive gallium and suspending a cell population to be tested in the gallium, flowing the test suspension through a cell counter and scintillation counter in an arrangement providing cell by cell series array in the flow, measuring radioactive emission of each cell and accumulating radioactive decay counts and cell numbers in a fashion convertible to a histogram plot of number of cells against counts per cell of decay incidents.
It is an important object of the invention to improve automated tissue examination by increasing the sensitivity, accuracy and speed thereof.
It is a further object of the invention to increase the uptake of radioactive tracer material by abnormal cells consistent with the preceding object.
It is a further object of the invention to suppress, at least in part, uptake of radioactive tracer by normal cells consistent with one or more of the preceding objects.